Method for depolluting fresh water and salt water bodies from crude oil, petroleum products and their derivatives

ABSTRACT

A method and a few compositions are disclosed, which are adapted to depollute fresh and sea water bodies from crude oil and petroleum product pollution by microbial action. The growth of micro-organisms capable of metabolizing hydrocarbons is exalted by certain combination of nutrients, such as lecithin as a phosphorus source, hydantoins, amides allophanates, polyamines, acyl-ureas and esters of the hydantoic and allantoic acids as the nitrogen sources. Ureido-derivatives of amides are also contemplated as additional nutrients.

This invention relates to a method for microbiologically removingpolluting agent from coasts, fresh water and sea water bodies as causedby crude oils, petroleum products and their derivatives.

The invention is likewise concerned with the preparation of mediaadapted to encourage the scattering of such pollutants whileconcurrently furnishing the nutrients which are essential for the growthof naturally occurring and/or added micro-organisms capable of oxidizinghydrocarbons and petroleum crude oils.

In the Italian Pat. No. 981,945 in the name of the same Applicantshereof there has been disclosed and claimed the preparation and the useof compositions based on salts which are poorly water-soluble and havebeen made lipophilic and floatable by means of a paraffinationprocedure, and which contain nitrogen and phosphorus in an assimilableform by aquatic micro-organisms capable of metabolizinghydrocarbonaceous materials.

In the U.S. patent application Ser. No. 738,697, now U.S. Pat. No.4,087,356 there has been disclosed and claimed the integration of suchcompositions of poorly water-soluble salts, more particularlyparaffinated magnesium and ammonium phosphates, with lipophilic floatingcompounds, which can float as themselves or are made floatable byparaffination and which contain slow-release nitrogen which can beassimilated by the micro-organisms concerned so as to obtain P+N/oilratios which are the most favourable for biological degradation.

Compounds which are adapted to this purpose were those belonging to thechemical class of the ureido-derivatives of aldehydes.

It had further been shown that biodegradation, while still encouraged bythese compounds, was further exalted by using nonionic dispersants.

These latter compounds unfold a synergistic action relative to that ofthe nutrients, thus causing a better distribution to occur of thenutrients themselves in the oily phase, said nutrients being containedin the formulations referred to above.

It has now been ascertained, and this is a first subject-matter of thepresent invention, that lecithin, a phosphatide ester occurring in manya natural produce of animal or vegetable nature, can efficiently replaceboth the phosphorus source and the dispersant of the formulationreferred to above.

As a matter of fact, lecithin is used up by the hydrocarbon-oxidizingmicro-organisms which are naturally occurring in sea water, as aphosphorus source.

In addition, inasmuch as lecithin is endowed of prominent emulsifyingproperties which are due to the presence of hydrophilic and lipophilicfunctional groups, it replaces, either wholly or in part, thecapillary-active agents in the formulations referred to hereinabove.

It has been found, moreover, and this is a further subject-matter of thepresent invention, that the compounds belonging to the chemical classesof hydantoins and amides, in addition to the aldehyde-urea condensationproducts mentioned above, can advantageously be used as nitrogen sourceswhich can be assimilated by the hydrocarbon-oxidizing micro-organisms.

As a matter of fact, while the fertilizing action of theureido-derivatives of aldehydes is subordinate to a chemical hydrolysis,the fertilizing action of hydantoins and amides unfolds itself byenzymic hydrolysis as brought about by the hydrocarbon-oxidizingmicro-organisms themselves.

Now, while the chemical hydrolysis of the ureido derivatives is governedby the physico-chemical factors of water, especially the temperature andthe pH value, environmental situations may arise, in which urea is setfree either in excess or defect of the nutritional requirements of thehydrocarbon-oxidizing micro-organisms: in the former case a slowdown ofthe biological degradation is brought about and, in the latter case,urea is inadequately utilized and this is an economical damage.

No such drawback is experienced when using chemical compounds of theclass of hydantoins and amides since the nitrogen contained therein isset free, and used up directly by the micro-organisms consistently withtheir actual demand.

It has been found, moreover, that a considerable increase of thebiological degradation velocity of the hydrocarbons is obtained whensuch nitrogen source, that is hydantoins and amides, are employedconcurrently with lecithin.

The formulations suggested by this invention can easily be applied inthe practice, as they do not require any special implementation but thatadopted hitherto by the first-aid means which use dispersants inhydrocarbon pollution cases.

The substances which can be used according to the method of thisinvention can be stored indefinitely, do not belong to the class of thetoxic products, can easily be carried to the place of use and canreadily be spread on the polluted areas: they permit within a shortdelay that pollution of fresh and sea water bodies by oil, petroleumproducts and their derivatives be done away with.

An important advantage of this method lies in the fact that the employedsubstances speed up a natural process of biological degradation of thepollutants without disturbing the ecological equilibrium.

That which has been outlined above and further working conditions willbe more clearly understood from the scrutiny of the ensuing examplesreported hereinafter to the only purpose of better illustrating theinvention without limiting the scope thereof.

In addition to what has been indicated above, the present Applicantshave also found, and this is another subject-matter of the presentinvention, that also the phosphatides, both synthetic and naturallyoccurring in many produces of both animal and vegetable origin, canconstitute both the phosphorus source and the dispersant.

It has also been found, and this is yet another subject-matter of thepresent invention, that there can be used with advantage as nitrogensources assimilable by the hydrocarbon-oxidizing micro-organisms, inaddition to the compounds belonging to the chemical classes ofhydantoins and amides, also compounds belonging to the chemical classesof the allophanates, the polyamines, the acyl-ureas and the esters ofthe hydantoic and allantoic acids.

As a matter of fact, also the fertilizing action of the nitrogenouscompounds listed above unfolds itself by enzymic hydrolysis as caused bythe hydrocarbon-oxidizing micro-organisms themselves.

It has been found, additionally, that an outstanding increase of thebiological degradation velocity of hydrocarbons is achieved wheneversuch nitrogen sources, that is, in addition to hydantoins and amides,the allophanates, the polyamines, the acyl-ureas and the esters of thehydantoic and allantoic acids, are employed together with thephosphatides, both synthetic and naturally occurring.

The formulations suggested by the present invention are easy to beapplied, do not require any special implementation, but those usedhitherto by the first-aid means which use dispersants in cases ofhydrocarbon pollution cases.

The substances which can be employed according to the method of thepresent invention can be stored indefinitely, do not belong to the classof toxic products, can easily by shipped to the place of use and canreadily be spread over the polluted areas and permit that the pollutionsof fresh and sea water bodies by crude oil, petroleum products and theirderivatives be readily put out.

An outstanding advantage of such method lies in the fact that theemployed substances quicken a natural process of biological degradationof the pollutants without interfering with the ecological equilibria.

That which has been set forth hereinabove and further features ofapplication will be better understood from the scrutiny of the followingexamples, which are reported herein to the only purpose of illustratingthe invention without limiting the scope thereof.

EXAMPLE 1

250-ml Erlenmayer flasks with ground-glass necks which contain 100 mlsof unsterilized sea water and 100 milligrams of Basra crude each, arecharged with;

(a) 5 milligrams of soybean lecithin and 5 milligrams urea

(b) 0.84 milligram of K₂ HPO₄ and 5 milligrams urea

(c) 5 milligrams urea

(d) control with no additions.

The flasks were incubated at 25° C. with rotatory stirring (100 rpm,eccentricity 5 centimeters). At the 0 time and every 5 days the residueof crude was determined by extraction with CCl₄ according to the methoddescribed in the above mentioned patent application.

The results which have been obtained are illustrated in FIG. 1, in whichthe ordinates show the residual crude expressed in percent, and theabscissae are the time in days.

EXAMPLE 2

250-ml Erlenmayer flasks having ground-glass necks and containing, each,100 mls of unsterilized sea water and 100 milligrams of Basra crude werecharged with:

(a) 5 milligrams of soybean lecithin and 6.5 milligrams oxamide

(b) 5 milligrams soybean lecithin and 13 milligrams ofD-L-5-phenylhydantoin

(c) 5 milligrams of soybean lecithin and 10 milligrams of thecondensation product of isovaleric aldehyde and urea obtained asdescribed in EXAMPLE 3.

(d) 5 milligrams of soybean lecithin and 15 milligrams of thecondensation product of 3-phenylpropionic aldehyde and urea, as obtainedunder the same conditions adopted for isovaleric aldehyde, for which seeEXAMPLE 3 hereinafter.

(e) control with no additions.

The flasks were incubated and the residual hydrocarbons were extractedas described hereinabove.

The results which have been obtained are illustrated in TABLE 1.

                  TABLE 1                                                         ______________________________________                                        Incubation time, days                                                         Nutrient formulations                                                                        7         12      19    25                                     ______________________________________                                        (a)            63.99 (°)                                                                        60.47   42.26 36.62                                  (b)            67.23     61.65   47.81 38.28                                  (c)            63.74     54.43   44.91 40.06                                  (d)            59.78     54.85   47.79 43.17                                  (e)            69.12     67.55   66.79 65.92                                  ______________________________________                                         (°) % residual oil.                                               

EXAMPLE 3

250-ml Erlenmayer flasks with ground-glass necks and containing, each,100 mls of unsterilized sea water and 100 milligrams of Basra crude werecharged with:

(a) 5 milligrams of soybean lecithin, 5 milligrams of an emulsifier(2,2'-hydroxydiethyloleylamide) and 10 milligrams of the condensationproduct of isovaleric aldehyde and urea, obtained in the following way:20 mls of an aqueous 25% solution of urea were supplemented by 1 mlglacial acetic acid and 2 mls of aldehyde, the mixture was allowed tostay stirred at room temperature for three hours. The precipitate thusobtained was collected on a paper filter, washed with water and dried ina vacuum oven at 40° C. for 24 hours.

(b) same composition as (a) but without the emulsifier.

(c) control, with no additions.

The results which have been obtained are illustrated in FIG. 2, in whichthe ordinates report the residual crude percentage and the abscissaeindicate the time in days.

EXAMPLE 4

250-ml Erlenmeyer flasks having ground-glass necks and containing, each,100 mls of unsterilized sea water and 100 mls of Basra crude werecharged with:

(a) 5 milligrams of soybean lecithin and 5 milligrams of urea

(b) 5 milligrams of dihexadecanoyl-phosphatidyl ethanolamina and 5milligrams of urea.

(c) 0.84 milligrams of K₂ HPO₄ and 5 milligrams of urea

(d) 5 milligrams urea

(e) control with no additions.

The flasks were incubated at 25° C. with rotary stirring (100 rpm,eccentricity 5 centimeters).

At the zero time and every 5 days the residue of crude was determined byextraction with CCl₄ according to the method disclosed in the abovementioned patent application.

The results which have been obtained are shown in FIG. 3 in which theordinates show the residual crude percentage and the abscissae are thetime in days.

EXAMPLE 5

250-ml Erlenmeyer flasks having ground-glass necks and containing, each,100 mls of unsterilized sea water and 100 milligrams of Basra crude werecharged with:

(a) See EXAMPLE 2

(b) See EXAMPLE 2

(c) See EXAMPLE 2

(d) See EXAMPLE 2

(e) 5 milligrams of soybean lecithin and 10 milligrams of ethylallophanate,

(f) 5 milligrams of soybean lecithin and 8 milligrams of spermidin,

(g) 5 milligrams of soybean lecithin and 12 milligrams of phenylacetylurea,

(h) 5 milligrams of soybean lecithin and 12 milligrams of butylhydantoinate,

(i) 5 milligrams of soybean lecithin and 8 milligrams of butylallantoinate.

The flasks were incubated and the residual hydrocarbons extracted asdescribed hereinabove.

The results which have been obtained are illustrated in TABLE 2.

                  TABLE 2                                                         ______________________________________                                        Incubation time, days                                                         Nutrient formulations                                                                        7         12      19    25                                     ______________________________________                                        (a)            63.99 (°)                                                                        60.47   42.26 36.62                                  (b)            67.23     61.65   47.81 38.28                                  (c)            63.74     54.43   44.91 40.06                                  (d)            59.78     54.85   47.79 43.17                                  (e)            66.12     59.77   46.00 36.12                                  (f)            67.24     60.44   47.32 39.39                                  (g)            65.66     56.11   45.28 37.21                                  (h)            61.88     56.19   47.29 39.18                                  (i)            60.03     54.28   45.14 37.13                                  ______________________________________                                         (°) residual oil, %. As can be seen, the results of TABLE 1 of         Example 2 have fully been confirmed as to items (a), (b), (c) and (d).   

We claim:
 1. In a method for depolluting fresh and sea water bodies fromcrude oil petroleum and products and their derivatives by spreading ontothe water bodies compounds which contain phosphorus and slow-releasenitrogen in a form which can be assimilated by aquatic microorganismscapable of metabolizing hydrocarbons, the improvement whichcomprises:using as said phosphorus source lecithin; and using as saidslow-release nitrogen source oxamide, at least about 6.5 milligrams ofsaid oxamide being present per 100 milligrams of pollutants, wherein atleast about 5 milligrams of soybean lecithin are present per 100milligrams of pollutants, said phosphorus and said nitrogen in saidcompound being present in an amount sufficient to increase the naturalbiodegradation of said pollutants caused by the metabolization ofhydrocarbons by said aquatic microorganisms.
 2. In a method fordepolluting fresh and sea water bodies from crude oil petroleum productsand their derivatives by spreading onto the water bodies compounds whichcontain phosphorus and slow-release nitrogen in a form which can beassimilated by aquatic microorganisms capable of metabolizinghydrocarbons, the improvement which comprises:using as said phosphorussource lecithin; and using as said slow-release nitrogen sourceD-L-5-phenylhydantoin, at least about 13 milligrams of saidD-L-5-phenylhydantoin being present per 100 milligrams of pollutants,wherein at least about 5 milligrams of soybean lecithin are present per100 milligrams of pollutants, said phosphorus and said nitrogen in saidcompound being present in an amount sufficient to increase the naturalbiodegradation of said pollutants caused by the metabolization ofhydrocarbons by said aquatic microorganisms.